What would the 2010 election look like without health-care reform?

Josh Kraushaar makes the case that health-care reform is a primary, not secondary, cause of Democratic distress in this election cycle. He marshals some persuasive evidence (though today's Politico disagrees that Democrats who opposed health-care reform are in good shape), though it's of course difficult to know how it stands up to a counterfactual in which health-care reform failed, or was never tried and was replaced by a push on cap-and-trade. As matters stand, President Obama and the Democrats are not popular and health-care reform is their most visible achievement. It makes sense that some campaigns would use it as a symbol of their failures.

I should say that I anticipated health-care reform would become more popular after passage. That was true for a couple of months, when the plan gained a couple of points, but now health-care reform's popularity is exactly where it was at passage. As the bill hasn't changed during that period, my sense is that has more to do with the deterioration in the economy (and thus in the Democrats' popularity, and the popularity of everything they've touched), but that's only a guess. The reality is that my political prediction on this didn't work out.

But since I'm interested in the counterfactual, let me offer it: How many seats do the Democrats lose in a world where everything is the same -- that is to say, health-care reform passed, and it was an ugly process -- but unemployment is 5.5 percent? How about in a world where unemployment is the same, but health-care reform was never attempted, and the Obama administration instead sought a price on carbon?

My best guess is that Democrats lose 25 fewer seats in the first world and five more seats in the second world (as cap-and-trade would provoke the same outrage on the right, and also harm some traditionally Democratic districts where they mine coal). But that's just my best guess. What's yours?